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Atmospheric pressure chemical ionization chamber cross section. Atmospheric pressure chemical ionization (APCI) is an ionization method used in mass spectrometry which utilizes gas-phase ion-molecule reactions at atmospheric pressure (10 5 Pa), [1] [2] commonly coupled with high-performance liquid chromatography (HPLC). [3]
The ion is selected in the second mass spectrometry stage MS2 then undergoes further fragmentation to form ion D + which is selected in the third mass spectrometry stage MS3 and detected. Multiple reaction monitoring (MRM) is the application of selected reaction monitoring to multiple product ions from one or more precursor ions, [3] [4] for ...
The use of the term mass spectroscopy is now discouraged due to the possibility of confusion with light spectroscopy. [1] [8] Mass spectrometry is often abbreviated as mass-spec or simply as MS. [1] Modern techniques of mass spectrometry were devised by Arthur Jeffrey Dempster and F.W. Aston in 1918 and 1919 respectively.
Peroxynitrate chemical ionization mass spectrometer at the US National Oceanic and Atmospheric Administration. CI mass spectrometry is a useful tool in structure elucidation of organic compounds. [3] This is possible with CI, because formation of [M+1] + eliminates a stable molecule, which can be used to guess the functional groups present. [3]
Both, the first mass analyzer and the collision cell are continuously exposed to ions from the source, in a time independent manner. [4] It is once the ions move into the third mass analyzer that time dependence becomes a factor. [4] The first quadrupole mass filter, Q1, is the primary m/z selector after the sample leaves the ionization source.
AP-MALDI is used in mass spectrometry (MS) in a variety of applications ranging from proteomics to drug discovery. Popular topics that are addressed by AP-MALDI mass spectrometry include: proteomics; mass analysis of DNA, RNA, PNA, lipids, oligosaccharides, phosphopeptides, bacteria, small molecules and synthetic polymers, similar applications ...
[4] [5] Since the early 2000s, LC–MS (or more specifically LC–MS/MS) has also begun to be used in clinical applications. [6] In addition to the liquid chromatography and mass spectrometry devices, an LC–MS system contains an interface that efficiently transfers the separated components from the LC column into the MS ion source.
Fourier-transform ion cyclotron resonance (FTICR) mass spectrometry is a high-resolution technique that can be used to determine masses with high accuracy. Many applications of FTICR-MS use this mass accuracy to help determine the composition of molecules based on accurate mass. This is possible due to the mass defect of the elements.